75ZT Community

I have returned from work tonight and remote fob will not lock or open the car

key opens the door but will not switch off the alarm, It also start starts the car but touch and go whether the alram goes off on starting, sometimes it stays on with the engine running !

the key will lock the car and set the alarm

( have recently fitted new batttery on the car but has been fine for a week, have also changed battery in fob for a new one, plenums are bone dry and battery reset not worked

does anyone know if this is connected to the immobiliser ?

Pretty certain it's not immobiliser. This only operates with the key in the ignition, and in any case the car starts OK.

I assume the red light still flashes on the keyfob? Could have been a duff replacement battery in the keyfob that has now gone dead?

You could try a resync: make sure the car is unlocked. Press the lock button on the keyfob four times in a row. On the fourth it should resync and lock.

Do you have a second key? Does that work?

been out in the car and it worked normally and i stopped and locked it about 3 times, now back on the drive and the gremlins are back with a vengeance.

It locks with the key but sometimes opens the windows at the same time and even though i have lazy locking i am not holding the key in the locked position as you would normally have to to open the windows, so it is trial and error whether it locks with windows closed or not, i have managed to close it now and am leaving alone as snow expected later

when it opens with the key the alarm doesnt switch off and goes off after the required time of about 15 seconds i think

with the alarm sounding starting the engine doesnt always turn it off, I have just tried the resynch but doesnt work and the second key is exactly the same

Do you have Pauls remote setup on this? Or is it standard?

i have Pauls set up but have pulled the fuse on it just in case it is related, and all still the same Mick

Trebor wrote:i have Pauls set up but have pulled the fuse on it just in case it is related, and all still the same Mick

That was what I was thinking.

even worse i have the BBS which wont shut up

Something doesn't make sense about it. Locking the car should close the windows anyway, not open them.

I wonder if there's a loose earth for the BCU (Body Control Unit). It has been known for one of the earth points at the bottom of the A pillars not to be done up properly, and only show up years later.

Other than that, I wonder if there's another wiring problem starting to show. We never explained why there was a partial short on the window bus wire, but it started working when we used a new piece of wire. Maybe the 'lock' or 'unlock' signal wire is suffering the same fate?

You do seem to get the tough ones.

I was thinking power or ground to the remote receiver in the das, but that could not explain the window problem. That would have to be BCU, or a signal line into it.

Duncan wrote:
I wonder if there's a loose earth for the BCU. It has been known for one of the earth points at the bottom of the A pillars not to be done up properly, and only show up years later.

I think that we went down that road at a meet when the previous problem was being investigated.

thanks for the input guys, Bernard is right i checked all the earth points before but can check again at the weekend in the daylight.

still the same today appears to be intermittent, got to work by unlocking with the key and starting the car within 15 seconds, drove the 20 odd miles to work and car locked with the fob no problem.( tried both fobs at this point and both worked to open and close so not a fob battery problem.)

Leaving work fob didnt work so i used the key again and alarm switched off when ignition started the car.

Got home fob not working and on locking car with the key windows came down again, so had to put key in ignition and use door switch to put up windows, car then locked with the key and alarm set.

Just pulled the FBH (Fuel burning heater.) fuse and symptoms still the same, i suspect a problem with the BCU as Duncan says but getting out of my depth

Rob, I'm sure we can meet up to have a look at it, you're not so far away. Only worry is trying to work in this weather without some shelter.

Duncan, that is a really kind offer i can come to you to save you the hassle, unfortunately cant get my car in the garage and shelter or maybe there is another venue we could look at ?

Unfortunately my garage is also full of stuff (well more cars and bits) as Paul will tell you.

Don't mind working outside but with snow and howling wind I think I'd give up too fast. Can't think of anywhere myself.

lets see how the weather goes because as long as i can continue to use the car as it is i am ok for now, its if it gets any worse when the problems will start such as windoews down and not back up again

Duncan wrote:Unfortunately my garage is also full of stuff (well more cars and bits) as Paul will tell you.

Don't mind working outside but with snow and howling wind I think I'd give up too fast. Can't think of anywhere myself.

My garage is available if it helps chaps.

raistlin wrote:

Duncan wrote:Unfortunately my garage is also full of stuff (well more cars and bits) as Paul will tell you.

Don't mind working outside but with snow and howling wind I think I'd give up too fast. Can't think of anywhere myself.

My garage is available if it helps chaps.

Now that might just be perfect.

At work tomorrow but the weekend might be good if travelling is OK.

Duncan wrote:

raistlin wrote:

Duncan wrote:Unfortunately my garage is also full of stuff (well more cars and bits) as Paul will tell you.

Don't mind working outside but with snow and howling wind I think I'd give up too fast. Can't think of anywhere myself.

My garage is available if it helps chaps.

Now that might just be perfect.

At work tomorrow but the weekend might be good if travelling is OK.

No problem Duncan. Any day and time will be OK

thanks for your kind offer Paul, knights is shining armour to the rescue - thanks.

I will make the time so whenever convenient Duncan but absolutely no pressure if you cant make it just let us know and of course weateher dependant

Got me wondering. Might also be water in the lock / unlock switch. Could be giving odd signals to the BCU if it is.

Duncan when you wonder i listen